JP2015207488A - Light source device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology capable of improving color conversion efficiency of a light source device with a simple structure.SOLUTION: A light source device emitting light from a light-emitting surface includes: a light-emitting member emitting light with first color; a first conversion member generating light with second color by causing excitation due to the light with the first color; and a second conversion member generating light with third color by causing excitation due to the light with the first color. The second conversion member is positioned so as to be closer to the light-emitting surface than the first conversion member, in a direction vertical to the light-emitting surface.

Description

  The present invention relates to a light source device and an image display device.

  Conventionally, a light source device having a B-LED and a conversion member having an R phosphor and a G phosphor has been proposed as a backlight device for a liquid crystal display device. B-LEDs are light emitting diodes (LEDs) that emit blue light. The R phosphor is a phosphor that emits red light when excited by blue light. The G phosphor is a phosphor that emits green light when excited by blue light. In such a light source device, red light is emitted from the R phosphor and green light is emitted from the G phosphor by the blue light from the B-LED. And the synthetic light which synthesize | combined the blue light from B-LED, the red light from R fluorescent substance, and the green light from G fluorescent substance is emitted from a light source device. If such a light source device is used, light having a wide color gamut can be obtained as light emitted from the light source device.

  In recent years, quantum dots have been proposed as phosphors (wavelength conversion elements) that can generate high-purity light by causing excitation. A quantum dot is a phosphor that emits light of a color corresponding to the particle size of the quantum dot in response to ultraviolet light or blue light. If quantum dots are used, red light or green light having a half-value width of about 40 nm can be obtained from blue light, and thus light in a higher color gamut can be obtained as light emitted from the light source device. A light source device using quantum dots is disclosed in Patent Document 1, for example. In the technique disclosed in Patent Document 1, a sheet-like member (quantum dot sheet) containing quantum dots is used as the conversion member.

  However, when a single conversion member (phosphor layer) contains a plurality of types of phosphors, the light emitted from the phosphors causes excitation of other phosphors, resulting in the color conversion efficiency of the conversion member. (Luminescence efficiency) decreases, and the color conversion efficiency of the light source device decreases. The color conversion efficiency is an efficiency for converting excitation light (light that causes excitation) into light of another color. For example, when an R phosphor and a G phosphor are included in one conversion member, excitation of the R phosphor is caused not only by blue light but also by green light. Here, in the G phosphor, it is assumed that blue light is converted to green light with a color conversion efficiency of 80%. In the R phosphor, blue light is converted into red light with a color conversion efficiency of 80%, and green light is converted into red light with a color conversion efficiency of 80%. In this case, the color conversion efficiency of the R phosphor becomes a value lower than 80%. Specifically, the color conversion efficiency of the R phosphor is 64% (= 80% color conversion efficiency from blue light to green light × 80% color conversion efficiency from green light to red light) and 80% (blue light Color conversion efficiency from red to red). As a result, the color conversion efficiency of the conversion member decreases, and the color conversion efficiency of the light source device decreases.

  A conventional technique for solving such a problem is disclosed in Patent Document 2, for example. In the technique disclosed in Patent Document 2, a plurality of conversion members arranged in a direction parallel to the light emitting surface of the light source device are used. In each conversion member, only one type of phosphor is used.

  However, when the technique disclosed in Patent Document 1 is used, in order to obtain light with small unevenness (luminance unevenness or color unevenness) as light from the light source device, a large number of small conversion members must be prepared. , Not easy to manufacture. For example, many small R conversion members (conversion members having R phosphors) and small G conversion members (conversion members having G phosphors) must be prepared. It is not easy to manufacture a plurality of R conversion members having the same color conversion efficiency and a plurality of G conversion members having the same color conversion efficiency.

JP 2012-022028 A JP 2012-142107 A

  An object of the present invention is to provide a technique capable of improving the color conversion efficiency of a light source device with a simple configuration.

The first aspect of the present invention is:
A light source device that emits light from a light emitting surface,
A light emitting member that emits light of a first color;
A first conversion member that generates light of a second color by being excited by the light of the first color;
A second conversion member that generates light of a third color by being excited by the light of the first color;
Have
The light source device is characterized in that the second conversion member is provided at a position closer to the light emitting surface than the first conversion member in a direction perpendicular to the light emitting surface.

The second aspect of the present invention is:
The light source device;
A display unit that displays an image on a screen by transmitting light from the light source device;
It is an image display apparatus characterized by having.

  According to the present invention, the color conversion efficiency of the light source device can be improved with a simple configuration.

Sectional drawing which shows an example of a structure of the liquid crystal display device which concerns on Example 1. FIG. The figure which shows an example of the blue light emitted from the light source which concerns on Example 1. FIG. The figure which shows an example of the synthetic light emitted from the 1st conversion member which concerns on Example 1. FIG. The figure which shows an example of the synthetic light emitted from the 2nd conversion member which concerns on Example 1. FIG. Sectional drawing which shows an example of a structure of the liquid crystal display device which concerns on Example 2. FIG. Sectional drawing which shows an example of a structure of the liquid crystal display device which concerns on Example 3. FIG. The figure which shows an example of the synthetic light emitted from the 2nd conversion member which concerns on Example 3. FIG. The figure which shows the modification of this invention The figure which shows the modification of this invention The figure which shows the modification of this invention The figure which shows the modification of this invention

<Example 1>
Hereinafter, a light source device and an image display device according to Embodiment 1 of the present invention will be described.
The light source device according to the present embodiment can be used as, for example, a light source device of an image display device having a display unit that displays an image on a screen by transmitting light from the light source device. Specifically, the light source device according to the present embodiment can be used as a light source device for an image display device such as a liquid crystal display device, an advertisement display device, and a sign display device. The light source device according to the present embodiment can also be used as a light source device for an image display device using a display element (for example, a MEMS (Micro Electro Mechanical System) shutter) different from the liquid crystal element of the liquid crystal display device. The light source device according to the present embodiment can also be used as a light source device for devices other than the image display device (interior lighting, street lamps, etc.).

FIG. 1 is a cross-sectional view (side view) showing an example of the configuration of the liquid crystal display device 100 according to the present embodiment. FIG. 1 is a cross-sectional view obtained by a plane perpendicular to the screen of the liquid crystal display device 100.
The liquid crystal display device 100 includes a liquid crystal panel 108, a liquid crystal panel holding member 109, a light source device, and the like. The light source device includes a light source 101, a light guide member 102, a reflection member 103, a light source holding member 104, a first conversion member 105, a second conversion member 106, a diffusion member 107, and the like.

The light source device according to the present embodiment emits light from the light emitting surface. In the example of FIG. 1, the surface of the diffusion member 107 on the liquid crystal panel 108 side corresponds to the light emitting surface.
The liquid crystal panel 108 is a display unit that displays an image on a screen by transmitting light from the light source device. The liquid crystal panel 108 has a plurality of liquid crystal elements, and the transmittance of each liquid crystal element is controlled according to image data output from an image output device (not shown). The light from the light source device is transmitted through the liquid crystal panel 108 (each liquid crystal element) with a transmittance corresponding to the image data, whereby an image is displayed on the screen. In the example of FIG. 1, the surface of the liquid crystal panel 108 opposite to the diffusion member 107 corresponds to the screen. In the example of FIG. 1, the area of the screen coincides with the area of the light emitting surface.
Note that the area of the screen may be different from the area of the light emitting surface.

  The liquid crystal panel holding member 109 holds the liquid crystal panel 108. In the example of FIG. 1, the distance between the diffusion member 107 and the liquid crystal panel 108 is held at a predetermined distance by the liquid crystal panel holding member 109.

  The light source 101 emits light of the first color. In the present embodiment, an example in which a B-LED that is a light emitting diode (LED) that emits blue light (blue light) is used as the light source 101 will be described. In this embodiment, the light emitted from the light source 101 is used as excitation light for the first conversion member 105 and the second conversion member 106.

Note that the light emitting elements included in the light source 101 are not limited to LEDs. For example, a laser element, an organic EL element, a cold cathode tube element, a plasma element, or the like may be used as the light emitting element.
The light emitted from the light source 101 is not limited to blue light. For example, the light emitted from the light source 101 may be red light, green light, cyan light, magenta light, yellow light, ultraviolet light, or the like.
Note that one light source 101 may include one light emitting element or a plurality of light emitting elements.

The light guide member 102 has an incident surface on which blue light emitted from the light source 101 is incident, and an emission surface that emits blue light incident on the incident surface. Specifically, the back surface of the light guide member 102 (surface opposite to the light emitting surface) is subjected to surface treatment such as embossing and printing. Then, the blue light emitted from the light source 101 enters the light guide member 102 from the side surface of the light guide member 102 and is reflected, diffused, and scattered on the back surface of the light guide member 102, and the front surface (light emission) of the light guide member 102. Output from the side of the surface). Light emitted from the light source 101 is guided to the light emitting surface side of the light source device by the light guide member 102. In the example of FIG. 1, a plate-like member (light guide plate) is used as the light guide member 102.
The light guide member 102 does not have to be a plate-like member.

The reflection member 103 is provided on the bottom surface of the light guide member 102 and is used to increase the reflection efficiency when the light emitted from the light source 101 is reflected on the bottom surface of the light guide member 102. In the example of FIG. 1, the reflecting member 103 is a plate-like member (reflecting plate).
The reflecting member 103 may be provided on a side surface of the light guide member 102 that is different from the incident surface on which light emitted from the light source 101 is incident. Thereby, the reflected light rate in such a side surface can be raised. Further, the reflecting member 103 may not be provided on the bottom surface of the light guide member 102 but may be provided only on the side surface of the light guide member 102.
Note that the reflecting member 103 may not be a plate-like member. For example, the reflection member 103 may be a sheet-like member.

The light source holding member 104 holds the light source 101. In the example of FIG. 1, the light guide member 102 and the reflection member 103 are also held at desired positions by the light source holding member 104.
The light source holding member 104 may have a heat dissipation structure that releases heat of the light source 101 to the outside.

  In the present embodiment, a member made up of the light source 101 and the light guide member 102 is referred to as a “light emitting member that emits light of the first color”. Note that the light emitting member may include at least one of the reflecting member 103 and the light source holding member 104.

The first conversion member 105 generates light of the second color by being excited by the light of the first color.
The second conversion member 106 generates light of the third color by being excited by the light of the first color.

In the present embodiment, the first conversion member 105 includes an R phosphor that is a phosphor that generates red light (red light) when excitation is caused by blue light. The second conversion member 105 includes a G phosphor that is a phosphor that generates green light (green light) when excitation is caused by blue light. In this embodiment, excitation light that causes excitation of the phosphor is converted into light having a longer wavelength than the excitation light by the phosphor. Therefore, the phosphor can also be called “light conversion element” or “wavelength conversion element”. “Wavelength” is the distance between adjacent identical phase points in the wave of electromagnetic waves. Short-wavelength light becomes ultraviolet light, long-wavelength light becomes infrared light, and intermediate-wavelength light between short and long wavelengths becomes visible light. The color of visible light changes with purple, blue, green, yellow, orange, and red as the wavelength increases.
In the present embodiment, the first conversion member 105 has quantum dots as the G phosphor, and the second conversion member 106 has quantum dots as the R phosphor.
In the present embodiment, the numbers (ratio) of the R phosphor and the G phosphor are adjusted so that white light is obtained as light emitted from the light source device. In the example of FIG. 1, both the first conversion member 105 and the second conversion member 106 are sheet-like members (quantum dot sheets).

In the example of FIG. 1, the second conversion member 106 is provided at a position closer to the light emitting surface than the first conversion member 105 in the direction perpendicular to the light emitting surface of the light source device. Specifically, the first conversion member 105 and the second conversion member 106 are provided on the light emission surface (front surface) side of the light guide member 102, and the first conversion member 105 is a light emitting member (light guide member 102). ) And the second conversion member 106.
Thereby, after the blue light is emitted from the light emitting member (the emission surface of the light guide member 102), the excitation of the first conversion member 105 and the excitation of the second conversion member 106 can be generated in that order.

Hereinafter, in order to simplify the description, it is assumed that no light is reflected inside the first conversion member 105 and the second conversion member 106.
Note that at least one of the first conversion member 105 and the second conversion member 106 may not have a phosphor, and the phosphor may not be a quantum dot. Further, at least one of the first conversion member 105 and the second conversion member 106 may not be a sheet-like member. For example, at least one of the first conversion member 105 and the second conversion member 106 may have a glass tube structure. The 1st conversion member 105 and the 2nd conversion member 106 should just be a member which can generate the light of another color from the irradiated light, The structure and shape are not specifically limited.
Note that the light emitted from the light source device is not limited to white light. For example, the light emitted from the light source device may be red light, green light, blue light, cyan light, magenta light, yellow light, or the like.
The light generated by excitation is not limited to red light and green light. For example, the light generated by the excitation may be blue light, cyan light, magenta light, yellow light, or the like.

The diffusing member 107 is provided closer to the light emitting surface than the second conversion member 106. The diffusion member 107 diffuses the light emitted from the second conversion member 106. Thereby, luminance unevenness and color unevenness of light emitted from the light source device can be reduced. As the diffusing member 107, for example, a diffusing plate, a diffusing sheet, a condensing sheet, a polarizing sheet, or the like can be used. The diffusing member 107 may be constituted by a single member or may have a structure in which a plurality of members are stacked.
Note that the light source device may not have the diffusing member 107.

  A specific example of the function and effect of the present embodiment will be described.

  As described above, blue light is emitted from the light source 101. The first color light emitted from the light source 101 is, for example, light having a shorter spectral peak wavelength than the third color light generated by the second conversion member 106. The spectrum of blue light emitted from the light source 101 has a peak (maximum value) in a wavelength range of not less than 440 nm and not more than 480 nm, for example. An example of a spectrum (spectral characteristic) of blue light emitted from the light source 101 is shown in FIG. The horizontal axis in FIG. 2 indicates the wavelength, and the vertical axis in FIG. 2 indicates the intensity. In this embodiment, the light source 101 is disposed on one or more side surfaces of the light guide member 102. The number and arrangement interval of the light sources 101 depend on the color of the light emitted from the light source device, the luminance of the light emitted from the light source device, the unevenness of the light emitted from the light source device (luminance unevenness and color unevenness), the guide of the light guide member 102. It is determined in consideration of optical performance and the like. In the example of FIG. 1, a plurality of light sources 101 are arranged along two sides of the light guide member 102.

  As described above, in the present embodiment, the first conversion member 105 is disposed on the light exit surface side of the light guide member 102 and is disposed between the light guide member 102 and the second conversion member 105. Yes. By arranging the first conversion member 105 at such a position, it is possible to suppress the green light generated by the second conversion member 106 from entering the first conversion member 105. Then, only blue light emitted from the light emitting member (light guide member 102) can be input to the first conversion member 105. As a result, since the first conversion member 105 generates red light only from blue light, the color conversion efficiency of the first conversion member 105 can be improved, and the color conversion efficiency of the light source device can be improved. it can. The color conversion efficiency is an efficiency for converting excitation light (light that causes excitation) into light of another color. The spectrum of red light generated in the first conversion member 105 has a peak in a wavelength range of, for example, 580 nm to 700 nm.

  Then, the first conversion member 105 emits synthetic light including blue light emitted from the light guide member 102 and red light generated by excitation of the first conversion member 105 (R phosphor). An example of the spectrum of the synthesized light emitted from the first conversion member 105 is shown in FIG. From FIG. 3, it can be seen that the spectrum of the synthesized light emitted from the first conversion member 105 has two peaks, a blue light spectrum peak and a red light spectrum peak.

  As described above, in the present embodiment, the second conversion member 106 is disposed on the emission surface side of the light guide member 102 and is closer to the light emitting surface of the light source device than the first conversion member 105. Has been placed. By arranging the second conversion member 106 at such a position, the combined light emitted from the first conversion member 105 is input to the second conversion member 106. As a result, in the second conversion member 106, green light is generated from blue light (blue light emitted from the light guide member 102) included in the combined light emitted from the first conversion member 105. The light of the third color generated by the second conversion member 106 is, for example, light having a shorter spectral peak wavelength than the light of the second color generated by the first conversion member 105. The spectrum of green light generated by the second conversion member 106 has a peak in a wavelength range of 500 nm or more and 550 nm or less, for example.

  Then, the second conversion member 106 emits synthetic light including synthetic light emitted from the first conversion member 105 and green light generated by excitation of the second conversion member 106 (G phosphor). That is, from the second conversion member 106, blue light emitted from the light guide member 102, red light generated by excitation of the first conversion member 105, and green light generated by excitation of the second conversion member 106, Containing synthetic light is emitted. An example of the spectrum of the synthesized light emitted from the second conversion member 106 is shown in FIG. From FIG. 4, it can be seen that the spectrum of the synthesized light emitted from the second conversion member 106 has three peaks: a blue light spectrum peak, a red light spectrum peak, and a green light spectrum peak. . The synthesized light having the spectrum shown in FIG. 4 is, for example, white light.

  As described above, according to this embodiment, the light source has a simple configuration that “the second conversion member is provided at a position closer to the light emitting surface than the first conversion member in the direction perpendicular to the light emitting surface of the light source device”. The color conversion efficiency of the apparatus can be improved. Specifically, “the first conversion member and the second conversion member are provided on the light exit surface side of the light guide member, and the first conversion member is provided between the light emitting member (light guide member) and the second conversion member”. The color conversion efficiency of the light source device can be improved with a simple configuration.

<Example 2>
Hereinafter, a light source device and an image display device according to Embodiment 2 of the present invention will be described. In the first embodiment, the configuration in which the first conversion member is disposed between the light guide member and the second conversion member has been described. In this embodiment, the light emitting member is a light source, the second conversion member is provided on the light exit surface side of the light guide member, and the first conversion member is disposed between the light source and the light guide member. The configuration will be described.

FIG. 5 is a cross-sectional view illustrating an example of the configuration of the liquid crystal display device 200 according to the present embodiment. FIG. 5 is a cross-sectional view obtained by a plane perpendicular to the screen of the liquid crystal display device 200.
The liquid crystal display device 200 includes a liquid crystal panel 208, a liquid crystal panel holding member 209, a light source device, and the like. The light source device includes a light source 201, a light guide member 202, a reflection member 203, a light source holding member 204, a first conversion member 205, a second conversion member 206, a diffusion member 207, and the like.

The liquid crystal panel 208 is the same member as the liquid crystal panel 108 of the first embodiment (FIG. 1).
The liquid crystal panel holding member 209 is the same member as the liquid crystal panel holding member 109 of the first embodiment.
The light source 201 is the same member as the light source 101 of the first embodiment. However, in this embodiment, the light source 201 corresponds to a “light emitting member”.

The first conversion member 205 has the same function as the first conversion member 105 of the first embodiment. However, the 1st conversion member 205 is provided in the position into which the blue light emitted from the light source 201 injects instead of the output surface side of a light guide member. In the example of FIG. 5, the first conversion member 205 is disposed between the light source 201 and the light guide member 202. By arranging the first conversion member 205 at such a position, it is possible to suppress the green light generated by the second conversion member 206 from entering the first conversion member 205. Then, only blue light emitted from the light emitting member (light source 201) can be input to the first conversion member 205. As a result, since the first conversion member 205 generates red light from only blue light, the color conversion efficiency of the first conversion member 205 can be improved, and the color conversion efficiency of the light source device can be improved. it can.

The first conversion member 205 emits combined light including blue light emitted from the light source 201 and red light generated by excitation of the first conversion member 205 (R phosphor).
The light guide member 202 is the same member as the light guide member 102 of the first embodiment. However, the combined light emitted from the first conversion member 205 is incident on the incident surface of the light guide member 202, and the combined light incident on the incident surface is emitted from the output surface of the light guide member 202.
The reflecting member 203 is the same member as the reflecting member 103 of the first embodiment.
The light source holding member 204 is the same member as the light source holding member 104 of the first embodiment.

  The second conversion member 206 has the same function as the second conversion member 106 of the first embodiment. Similar to the first embodiment, the second conversion member 206 is provided on the light exit surface side of the light guide member 202. However, the combined light emitted from the first conversion member 205 is input to the second conversion member 206 via the light guide member 202. As a result, in the second conversion member 206, green light is generated from blue light (blue light emitted from the light guide member 202) included in the combined light emitted from the first conversion member 205. Then, the second conversion member 206 emits synthetic light including synthetic light emitted from the first conversion member 205 and green light generated by excitation of the second conversion member 206 (G phosphor).

As described above, according to the present embodiment, the color conversion efficiency of the light source device can be improved with a simple configuration. Specifically, “a first conversion member is provided at a position where the first color light emitted from the light source is incident, and the combined light from the first conversion member is guided to the light emitting surface side of the light source device. The color conversion efficiency can be improved with a simple configuration that “the second conversion member is provided on the light exit surface side of the optical member”.
Further, in this embodiment, since the first conversion member is disposed immediately above the light source, the number of phosphors (quantum dots) used in the first conversion member can be reduced, and the manufacturing cost of the light source device is reduced. can do.

<Example 3>
Hereinafter, a light source device and an image display device according to Embodiment 3 of the present invention will be described. In the second embodiment, the configuration that can reduce the number of phosphors (quantum dots) used in the first conversion member has been described. In the present embodiment, a configuration that can reduce the number of phosphors (quantum dots) used in the second conversion member will be described.

FIG. 6 is a cross-sectional view illustrating an example of the configuration of the liquid crystal display device 300 according to the present embodiment. FIG. 6 is a cross-sectional view obtained by a plane perpendicular to the screen of the liquid crystal display device 300.
The liquid crystal display device 300 includes a liquid crystal panel 308, a liquid crystal panel holding member 309, a light source device, and the like. The light source device includes a second light source 301, a third light guide member 302, a reflection member 303, a light source holding member 304, a first conversion member 305, a second conversion member 306, a diffusion member 307, a first light source 310, and a first light guide. Member 311 and the like.

The liquid crystal panel 308 is the same member as the liquid crystal panel 108 of the first embodiment (FIG. 1).
The liquid crystal panel holding member 309 is the same member as the liquid crystal panel holding member 109 of the first embodiment.
The second light source 301 is the same member as the light source 101 of the first embodiment. However, in the embodiment, the light emitted from the second light source 301 is used as the excitation light for the first conversion member 305, but is not used as the excitation light for the second conversion member 306.
The third light guide member 302 is the same member as the light guide member 102 of the first embodiment.
The reflection member 303 is the same member as the reflection member 103 of the first embodiment.
The light source holding member 304 is the same member as the light source holding member 104 of the first embodiment.
The first conversion member 305 is the same member as the first conversion member 105 of the first embodiment.
In the present embodiment, as in the first embodiment, a member having the second light source 301 and the third light guide member 302 is used as the light emitting member.

  The first light source 310 emits light of the first color. In this embodiment, an example in which a B-LED is used as the first light source 310 will be described. In the present embodiment, the light emitted from the first light source 310 is used as excitation light for the second conversion member 306.

In addition, the light emitting element which the 1st light source 310 has is not restricted to LED. For example, a laser element, an organic EL element, a cold cathode tube element, a plasma element, or the like may be used as the light emitting element.
Note that the light emitted from the first light source 310 is not limited to blue light. For example, the light emitted from the first light source 310 may be red light, green light, cyan light, magenta light, yellow light, ultraviolet light, or the like.
Note that one first light source 310 may have one light emitting element or a plurality of light emitting elements.
In the example of FIG. 6, the first light source 310 is provided on the same side as the second light source 301 in a plane parallel to the light emitting surface of the light source device, but this is not restrictive. The first light source 310 may be provided on a side different from the second light source 301 on a surface parallel to the light emitting surface of the light source device.

  The second conversion member 306 has the same function as the second conversion member 106 of the first embodiment. However, the second conversion member 306 is provided not at the emission surface side of the third light guide member 302 but at a position where the blue light emitted from the first light source 310 is incident. As a result, in the second conversion member 306, green light is generated from the blue light emitted from the first light source 310. From the second conversion member 306, the combined light (second combined light) including the blue light emitted from the first light source 310 and the green light generated by the excitation of the second conversion member 306 (G phosphor). ) Is issued. An example of the spectrum of the second synthesized light emitted from the second conversion member 306 is shown in FIG. From FIG. 7, it can be seen that the spectrum of the second synthesized light emitted from the second conversion member 306 has two peaks, that is, the peak of the blue light spectrum and the peak of the green light spectrum.

  As in the first embodiment, the first conversion member 305 generates blue light emitted from the light emitting member (third light guide member 302) and excitation of the first conversion member 305 (R phosphor). First synthesized light including red light is emitted.

The first light guide member 311 has a first incident surface, a second incident surface, and an exit surface. The first incident surface is an incident surface on which the first synthesized light emitted from the first conversion member 305 is incident, and the second incident surface is incident on which the second synthesized light emitted from the second conversion member 306 is incident. Surface. The exit surface of the first light guide member 311 is an exit surface that emits third synthesized light including the first synthesized light incident on the first incident surface and the second synthesized light incident on the second incident surface. . In the example of FIG. 6, the first incident surface is a side surface that is present on the first conversion member 305 side among the side surfaces of the first light guide member 311. The second incident surface is the back surface of the first light guide member 311. The exit surface of the first light guide member 311 is the front surface of the first light guide member 311. In the example of FIG. 6, a plate-like member (light guide plate) is used as the first light guide member 311.
Note that the first light guide member 311 may not be a plate-like member.

The diffusion member 307 has the same function as the diffusion member 107 of the first embodiment. However, in this embodiment, the diffusing member 307 diffuses the third combined light emitted from the emission surface of the first light guide member 311.

  According to the present embodiment, the color of the light source device can be achieved with a simple configuration that “the light emitting member, the first light source, the first light guide member, the first conversion member, and the second conversion member are arranged at the positions described above”. Conversion efficiency can be improved. Specifically, by arranging the first conversion member between the first light guide member and the third light guide member, the green light generated by the second conversion member is prevented from entering the first conversion member. be able to. And only the blue light emitted from the light emission member (3rd light guide member) can be input into a 1st conversion member. As a result, since the first conversion member generates red light only from blue light, the color conversion efficiency of the first conversion member can be improved, and the color conversion efficiency of the light source device can be improved.

  Moreover, by arranging the second conversion member between the first light source and the first light guide member, it is possible to suppress the red light generated by the first conversion member from entering the second conversion member. And only the blue light emitted from the 1st light source can be inputted into the 2nd conversion member. As a result, since the second conversion member generates green light only from blue light, the color conversion efficiency of the second conversion member can be improved as compared with the first and second embodiments, and the color conversion efficiency of the light source device can be improved. Can be improved as compared with the first and second embodiments.

  In the present embodiment, the color of light emitted from the light source device can be changed by using the first light source and the second light source. For example, the color of light emitted from the light source device can be changed by changing the ratio of the light emission luminance of the first light source and the light emission luminance of the second light source. Specifically, the luminance of the red light generated by the first conversion member can be changed by changing the emission luminance of the second light source, and the intensity of the magenta color component in the light emitted from the light source device is changed. be able to. Then, by changing the light emission luminance of the first light source, the luminance of the green light generated by the second conversion member can be changed, and the intensity of the cyan component in the light emitted from the light source device can be changed. .

  Further, in this embodiment, since the second conversion member is disposed immediately above the first light source, the number of phosphors (quantum dots) used in the second conversion member can be reduced, and the manufacturing cost of the light source device can be reduced. Can be reduced.

  In addition, the structure of Examples 1-3 mentioned above is an example to the last, and this invention is not limited to these structures. Configurations obtained by adding various modifications and changes to the configurations of the first to third embodiments are also included in the present invention.

  For example, as shown in FIG. 8, a second conversion member 806 and a second light guide member 811 may be used instead of the second conversion member 306 and the first light guide member 311 in FIG. 6. In the example of FIG. 8, the second light guide member 811 has a third entrance surface, a fourth entrance surface, and an exit surface. The third incident surface is an incident surface on which the first synthesized light emitted from the first conversion member 305 is incident, and the fourth incident surface is an incident surface on which the blue light emitted from the first light source 310 is incident. . The emission surface of the second light guide member 811 includes fourth synthetic light (= third synthetic light) including the first synthetic light incident on the third incident surface and the first color light incident on the fourth incident surface. It is an emission surface which radiates | emits. As the second light guide member 811, the same member as the first light guide member 311 can be used. The second conversion member 806 is provided on the light exit surface side of the second light guide member 911.

  The fourth conversion light emitted from the emission surface of the second light guide member 811 is input to the second conversion member 806. As a result, in the second conversion member 806, green light is generated from the blue light included in the fourth combined light. The second conversion member 806 emits synthetic light including the fourth synthetic light and green light generated by the excitation of the second conversion member 806. The combined light emitted from the second conversion member 806 is input to the diffusion member 307.

According to the configuration of FIG. 8, by arranging the first conversion member between the second light guide member and the third light guide member, the green light generated by the second conversion member is incident on the first conversion member. Can be suppressed. And only the blue light emitted from the light emission member (3rd light guide member) can be input into a 1st conversion member. As a result, since the first conversion member generates red light only from blue light, the color conversion efficiency of the first conversion member can be improved, and the color conversion efficiency of the light source device can be improved.
Moreover, the color of the light emitted from the light source device can be changed by using the first light source and the second light source.

  As shown in FIG. 9, the second light source 301 is used as a light emitting member. Instead of the third light guide member 302, the first conversion member 305, and the first light guide member 311 in FIG. The light guide member 902, the first conversion member 905, and the fourth light guide member 911 may be used. In the example of FIG. 9, the first conversion member 905 is provided at a position where blue light emitted from the second light source 301 enters. The fifth light guide member 902 has an incident surface on which the first synthesized light emitted from the first conversion member 905 is incident and an emission surface that emits the first synthesized light incident on the incident surface. As the fifth light guide member 902, the same member as the third light guide member 302 can be used. The fourth light guide member 911 has a fifth incident surface, a sixth incident surface, and an output surface. The fifth incident surface is an incident surface on which the first synthesized light emitted from the emission surface of the fifth light guide member 902 is incident, and the sixth incident surface is the second synthesized light emitted from the second conversion member 306. Is an incident surface on which is incident. The emission surface of the fourth light guide member 911 emits fifth synthesized light (= third synthesized light) including the first synthesized light incident on the fifth incident surface and the second synthesized light incident on the sixth incident surface. This is the exit surface. As the fourth light guide member 911, the same member as the first light guide member 311 can be used.

  Further, as shown in FIG. 10, the second light source 301 may be used as a light emitting member. And instead of the 3rd light guide member 302 of FIG. 6, the 1st conversion member 305, the 2nd conversion member 306, and the 1st light guide member 311, the 5th light guide member 1002, the 1st conversion member 1005, the 1st. Two conversion members 1006 and a sixth light guide member 1011 may be used. In the example of FIG. 10, the first conversion member 1005 is provided at a position where blue light emitted from the second light source 301 enters. The fifth light guide member 1002 is the same member as the fifth light guide member 902 of FIG. The sixth light guide member 1011 has a seventh incident surface, an eighth incident surface, and an output surface. The seventh incident surface is an incident surface on which the first combined light emitted from the emission surface of the fifth light guide member 1011 is incident, and the eighth incident surface is incident on the blue light emitted from the first light source 310. The incident surface. The emission surface of the sixth light guide member 1011 emits the sixth synthesized light (= third synthesized light) including the first synthesized light incident on the seventh incident surface and the blue light incident on the eighth incident surface. Surface. As the sixth light guide member 1011, the same member as the first light guide member 311 can be used. The second conversion member 1006 is provided on the emission surface side of the sixth light guide member.

That is, the configuration of the second embodiment may be combined with the configurations of FIGS.
According to the configuration of FIGS. 9 and 10, since the first conversion member is arranged in a straightforward manner of the second light source, the number of phosphors used in the first conversion member can be reduced, and the manufacturing cost of the light source device can be reduced. Can be reduced. In particular, according to the configuration of FIG. 9, the first conversion member is arranged directly in the second light source, and the second conversion member is arranged immediately above the first light source. Therefore, both the number of phosphors used in the first conversion member and the number of phosphors used in the second conversion member can be reduced, and the manufacturing cost of the light source device can be further reduced.

Further, the light source device may not have the light guide member 102 of FIG. Specifically, as shown in FIG. 11, a plurality of light sources 101 arranged in the region of the light emitting surface of the light source device may be used as the light emitting member. In the example of FIG. 11, the first conversion member 105 and the second conversion member 106 are provided on the light emitting surface side of the plurality of light sources 101, and the light emitted from the plurality of light sources 101 is transmitted to the first conversion member 105. Incident. Also in the configuration of FIG. 11, the same effect as the configuration of FIG. 1 can be expected. Similarly, the light source device may not have the third light guide member 302 of FIGS.

101, 201: Light source 301: Second light source 102, 302: Light guide member 105, 205, 305, 905, 1005: First conversion member 106, 206, 306, 806, 1006: Second conversion member

Claims (18)

A light source device that emits light from a light emitting surface,
A light emitting member that emits light of a first color;
A first conversion member that generates light of a second color by being excited by the light of the first color;
A second conversion member that generates light of a third color by being excited by the light of the first color;
Have
The light source device, wherein the second conversion member is provided at a position closer to the light emitting surface than the first conversion member in a direction perpendicular to the light emitting surface. The light source device according to claim 1, wherein at least one of the first conversion member and the second conversion member includes a phosphor. The light source device according to claim 1, wherein at least one of the first conversion member and the second conversion member includes a quantum dot. The light of the first color is light whose spectral peak wavelength is shorter than the light of the third color;
4. The light source device according to claim 1, wherein the light of the third color is light having a shorter peak wavelength than the light of the second color. 5. The first color is blue;
The second color is red;
The light source device according to claim 1, wherein the third color is green. The spectrum of the first color light has a peak in a wavelength range of 440 nm to 480 nm,
The spectrum of the light of the second color has a peak in a wavelength range of 580 nm to 700 nm,
The light source device according to any one of claims 1 to 5, wherein the spectrum of the light of the third color has a peak in a wavelength range of 500 nm or more and 550 nm or less. The light source device according to claim 1, wherein at least one of the first conversion member and the second conversion member is a sheet-like member. The light source device according to claim 1, wherein at least one of the first conversion member and the second conversion member has a glass tube structure. In the first conversion member and the second conversion member, after the light of the first color is emitted from the light emitting member, the excitation of the first conversion member and the excitation of the second conversion member are in that order. It is provided so that it may arise, The light source device of any one of Claims 1-8 characterized by the above-mentioned. The light source device according to claim 1, wherein the first conversion member is provided between the light emitting member and the second conversion member. The light emitting member is
A light source that emits light of the first color;
A light guide member having an incident surface on which light of the first color emitted from the light source is incident, and an emission surface that emits light of the first color incident on the incident surface;
Have
11. The light source device according to claim 1, wherein the first conversion member and the second conversion member are provided on the light exit surface side of the light guide member. A light guide member;
The light emitting member is a light source that emits light of the first color,
The first conversion member is provided at a position where light of the first color emitted from the light source is incident,
From the first conversion member, the first color light emitted from the light source and incident on the first conversion member, and the second color light generated by excitation of the first conversion member, Synthetic light containing is emitted,
The light guide member has an incident surface on which the combined light emitted from the first conversion member is incident, and an output surface that emits the combined light incident on the incident surface,
The light source device according to claim 1, wherein the second conversion member is provided on the light exit surface side of the light guide member. A first light source that emits light of the first color;
A first light guide member;
Further comprising
The first conversion member is provided at a position where the first color light emitted from the light emitting member is incident,
The second conversion member is provided at a position where the light of the first color emitted from the first light source enters,
From the first conversion member, the first color light emitted from the light emitting member and incident on the first conversion member, the second color light generated by excitation of the first conversion member, and First synthesized light containing is emitted,
From the second conversion member, the first color light emitted from the first light source and incident on the second conversion member, and the third color light generated by excitation of the second conversion member; , Second synthesized light including
The first light guide member has a first incident surface on which the first synthetic light emitted from the first conversion member is incident, and a second incident on which the second synthetic light emitted from the second conversion member is incident. And an exit surface for emitting third synthetic light including the first synthetic light incident on the first incident surface and the second synthetic light incident on the second incident surface. The light source device according to any one of claims 1 to 8. A first light source that emits light of the first color;
A second light guide member;
Further comprising
The first conversion member is provided at a position where the first color light emitted from the light emitting member is incident,
From the first conversion member, the first color light emitted from the light emitting member and incident on the first conversion member, the second color light generated by excitation of the first conversion member, and First synthesized light containing is emitted,
The second light guide member has a third incident surface on which the first synthesized light emitted from the first conversion member is incident, and a fourth light on which the first color light emitted from the first light source is incident. An exit surface, and an exit surface that emits fourth synthesized light including the first synthesized light incident on the third incident surface and the first color light incident on the fourth incident surface. ,
The light source device according to claim 1, wherein the second conversion member is provided on a side of the emission surface of the second light guide member. The light emitting member is
A second light source that emits light of the first color;
A third light guide member having an incident surface on which light of the first color emitted from the second light source is incident and an emission surface that emits light of the first color incident on the incident surface; ,
Have
The light source device according to claim 13 or 14, wherein the first conversion member is provided on a side of the emission surface of the third light guide member. A first light source that emits light of the first color;
A fourth light guide member;
A fifth light guide member;
Further comprising
The light emitting member is a second light source that emits light of the first color,
The first conversion member is provided at a position where the light of the first color emitted from the second light source is incident,
The second conversion member is provided at a position where the light of the first color emitted from the first light source enters,
From the first conversion member, the first color light emitted from the second light source and incident on the first conversion member, and the second color light generated by excitation of the first conversion member, First synthetic light including
From the second conversion member, the first color light emitted from the first light source and incident on the second conversion member, and the third color light generated by excitation of the second conversion member; , Second synthesized light including
The fifth light guide member has an incident surface on which the first synthesized light emitted from the first conversion member is incident, and an emission surface that emits the first synthesized light incident on the incident surface. ,
The fourth light guide member includes a fifth incident surface on which the first synthetic light emitted from the emission surface of the fifth light guide member is incident, and the second synthetic light emitted from the second conversion member. A sixth incident surface that is incident, and an emission surface that emits fifth synthetic light including the first synthetic light incident on the fifth incident surface and the second synthetic light incident on the sixth incident surface; It has, The light source device of any one of Claims 1-8 characterized by the above-mentioned. A first light source that emits light of the first color;
A fifth light guide member;
A sixth light guide member;
Further comprising
The light emitting member is a second light source that emits light of the first color,
The first conversion member is provided at a position where the light of the first color emitted from the second light source is incident,
From the first conversion member, the first color light emitted from the second light source and incident on the first conversion member, and the second color light generated by excitation of the first conversion member, First synthetic light including
The fifth light guide member has an incident surface on which the first synthesized light emitted from the first conversion member is incident, and an emission surface that emits the first synthesized light incident on the incident surface. ,
The sixth light guide member has a seventh incident surface on which the first synthesized light emitted from the emission surface of the fifth light guide member is incident, and the light of the first color emitted from the first light source. , Which emits the sixth combined light including the eighth incident surface on which the first incident light enters, and the first synthetic light incident on the seventh incident surface and the first color light incident on the eighth incident surface. Surface, and
The light source device according to claim 1, wherein the second conversion member is provided on the side of the emission surface of the sixth light guide member. The light source device according to any one of claims 1 to 17,
A display unit that displays an image on a screen by transmitting light from the light source device;
An image display device comprising:

Images